DeFelsko PosiTest AT Guide D'utilisation page 3

The PosiTest AT Pull-Off Adhesion Tester measures the force
required to pull a specified test diameter of coating away from its
substrate using hydraulic pressure. The pressure is displayed on
a digital LCD and represents the coating's strength of adhesion to
the substrate.
In accordance with ASTM D4541, D7234, ISO 4624 and
others, the PosiTest AT evaluates the adhesion (pull-off strength)
of a coating by determining the greatest tensile pull-off force that
it can bear before detaching. Breaking points, demonstrated by
fractured surfaces, occur along the weakest plane within the
system consisting of the dolly (loading fixture, stub), glue, coating
layers and substrate.
This quick guide summarizes the basic functions of the instrument.
Download a full instruction manual at: www.defelsko.com/manuals
Basic Steps to Perform a Pull-Off Test
1. Dolly & Coating Preparation
The dolly and the coating are cleaned and abraded (see pg.2).
2. Glue & Dolly Application
The glue is prepared and applied to the dolly. The dolly is
is then adhered to the coated surface and the glue is allow-
ed to cure (see pg. 2).
3. Test Area Separation - optional
The test area of the coating is isolated from the area
surrounding the dolly by cutting or drilling (see pg. 3).
4. Pull-Off Test
a) PosiTest AT-M (manual)
b) PosiTest AT-A (automatic) (see pg. 7)
5. Analysis of Test Results
The dolly and the coating are examined and evaluated to
determine the nature of the coating failure (see pg. 4).
Introduction
(see pg. 5)
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